JP3794045B2 - Inkjet recording device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet recording apparatus that performs printing by spraying ink on paper.
[0002]
[Prior art]
A communication device such as a facsimile device and an information processing device such as a personal computer usually have a recording device capable of printing these data on paper so as to record data consisting of characters and figures as visual information. In this recording device, various printing methods such as impact method, thermal method, ink jet method, etc. are adopted, but in recent years, ink jet method that is excellent in quietness and can print on paper of various materials is adopted. Inkjet recording apparatuses that have been used are frequently used.
[0003]
In the above-described ink jet recording apparatus, an ink jet head having a large number of nozzles and a paper are arranged to face each other, and ink is ejected from nozzles corresponding to output data and sprayed onto the paper while main scanning the ink jet head. Characters and figures are printed on. Accordingly, the ink jet recording apparatus that performs printing by such an operation requires quick drying of the ink so that the ink sprayed onto the paper does not stain other than the sprayed portion, while achieving high-definition print output. In addition, since the nozzle is required to have a small diameter, the nozzle is easily clogged due to the solidification of the ink. When the nozzle is clogged, the clogged portion is not printed, and therefore, in a facsimile apparatus that records only by printing output, there arises a big problem of missing recorded data. The problem of missing recording data also occurs when ink runs out.
[0004]
Therefore, the conventional ink jet recording apparatus detects nozzle clogging or out of ink by detecting the presence or absence of ink when ink is sprayed from each nozzle onto a sheet through a sensor.
[0005]
[Problems to be solved by the invention]
By the way, when nozzle clogging is detected, head cleaning is performed to eliminate clogging, or the nozzle is continuously used until the number of clogged nozzles exceeds the allowable number, or the contents of the output data After various processes such as correcting the image are performed, printing is continued. On the other hand, when it is detected that ink has run out, it is impossible to print on the paper, and instead of performing printing, for example, in the facsimile apparatus, proxy reception or the like is performed. Therefore, clogging and running out of ink have a great difference in continuity of printing, and processing after detection is different. Therefore, discrimination between the two is an extremely important requirement for the ink jet recording apparatus.
[0006]
However, with the configuration in which only the presence or absence of ink is detected as in the conventional case, it is possible to determine whether ink has run out or clogged when ink is completely ejected without ink being ejected. If the ink has run out to the extent that no ink is supplied to the nozzle, nozzles that do not eject ink are partially detected, as in the case of clogging, and it is extremely difficult to distinguish between ink running out and clogging. There is a problem.
[0007]
Therefore, the present invention aims to provide an ink jet recording apparatus capable of easily and surely discriminating ink clogging and clogging even when ink has run out to such an extent that ink is not sufficiently supplied to all nozzles. To do.
[0008]
[Means for Solving the Problems]
[0009]
[0010]
In order to solve the above-mentioned object, the invention of claim 1 detects ink shortage and nozzle clogging by detecting the presence or absence of ink when ink is sprayed onto a sheet from a plurality of nozzles of an inkjet head. In the ink jet recording apparatus having an abnormality detection unit, the abnormality detection unit includes an ink detection unit that detects the presence or absence of the ink, a nozzle identification unit that identifies a clogged nozzle based on the presence or absence of the ink, and the above The head cleaning means for cleaning the head so as to eliminate clogging, and the nozzle specified by the nozzle specifying means are acquired before and after the head cleaning, and based on the correlation between these nozzles , all the nozzles are acquired. fully determine which one out of ink and clogging of the degree to which ink is not supplied Te It is characterized by having a determining means for. As a result, clogging occurs under the same situation as in the case of clogging in which nozzles that do not eject ink are partially detected so that ink is not sufficiently supplied to all nozzles. Since ink outage and clogging are discriminated based on the correlation between the nozzles, the ink outage and clogging can be discriminated easily and reliably. Further, since the determination is made based on the nozzles before and after the head cleaning, it is possible to more reliably determine whether ink has run out or clogged.
[0011]
The invention of claim 2 is characterized in that the nozzle specifying means of claim 1 specifies all nozzles of the inkjet head in block units. As a result, the clogged nozzles can be identified in units of blocks, so that the time required to detect ink clogging and clogging can be shortened.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The case where the present invention is applied as an ink jet recording apparatus of a facsimile apparatus will be described below with reference to FIGS.
[0013]
The ink jet recording apparatus according to this embodiment is built in a facsimile apparatus as shown in FIG. The facsimile apparatus includes an apparatus main body 1 including a lower cover 2 and an upper cover 3 serving as a casing, and a receiver 4 disposed on the side of the apparatus main body 1. As shown in FIG. 4, the apparatus main body 1 takes a document 20 into the apparatus from above the upper cover 3, and then ejects the document 20 from the opening 3 a and an image of the document 20 conveyed by the document feeder 21. And a sheet cassette 5 detachably provided from the front surface (left side surface in the figure) of the lower cover 2.
[0014]
A large number of sheets 6 are stacked and accommodated in the sheet cassette 5, and these sheets 6 are urged upward at the front end side located on the right side of the sheet cassette 5 in the figure, The uppermost paper 6 is brought into contact with a paper feed roller 7 provided in the vicinity of the paper feed opening 5 a of the paper cassette 5.
[0015]
The paper feed roller 7 feeds the paper 6 in the paper cassette 5 from the paper feed port 5a to the paper feeding device 8. The paper feeding device 8 that feeds the paper 6 includes a paper leading edge detection sensor 11 that detects the leading edge of the paper 6, a curved paper guide 9 that regulates the feeding direction of the paper 6, and a paper feeding that feeds the paper 6. The paper 6 passes through the printing unit 12 by the paper feed roller 10 and is conveyed to the discharge roller 55. Then, from the printing unit 12 to the carry-out side of the paper 6, the paper that is conveyed along the platen 13 and the paper guide 14 that regulates the traveling direction of the printed paper 6, and the paper that is discharged out of the apparatus by the discharge roller 55. 6 are disposed in this order. The paper discharge table 15 also serves as a cover for the paper cassette 5.
[0016]
The printing unit 12 includes a platen 13 that also serves as a chute mounted between the paper feed roller 10 and the discharge roller 55, and an ink jet recording apparatus main body 30 that prints by spraying ink on the paper 6. . As shown in FIG. 5, the ink jet recording apparatus main body 30 includes four ink jet heads 31... For ejecting yellow Y, cyan C, magenta M, and black B inks, and ink jet heads 31. The joined carriage 32, guide members 34a and 34b that support the carriage 32 movably in the main scanning direction X, and the carriage 32 is reciprocated in the main scanning direction X along the guide members 34a and 34b (main scanning). And a traveling mechanism 33 to be operated.
[0017]
As shown in FIG. 6, each of the inkjet heads 31 includes a plurality of nozzles 31 b... That eject ink by driving a piezoelectric element. The ink jet head 31 may eject ink by a bubble method. These nozzles 31b ... are arranged at regular intervals in the sub-scanning direction Y orthogonal to the main scanning direction X, and the nozzle numbers P (0) to P (0) to be able to identify the nozzles 31b ... individually. P (N) is set. The ink jet head 31 opposes the nozzle surface 31a on which these nozzles 31b... Are formed so as to be parallel to the paper 6. The ink ejected from each nozzle 31b. 6 is sprayed in the vertical direction. As a result, as shown in FIG. 4, in the printing unit 12, the main scanning of the four inkjet heads 31... By the inkjet recording apparatus main body 30 and the sub-scanning of the sheet 6 by the paper feed roller 10 are repeated. As a result, black dots or color dots are printed on the entire surface or a part of the paper 6 by spraying ink.
[0018]
In the vicinity of the printing unit 12, an optical sensor that can optically detect the ink ejected from the inkjet head 31, and a vibration sensor that can detect ink based on vibration when the ink reaches the paper 6. An ink detecting sensor 19 (ink detecting means) is provided, and the ink detecting sensor 19 detects whether ink is sprayed from the nozzles 31b. Yes. A paper guide 14 for restricting the traveling direction of the printed paper 6 and a paper 6 discharged outside the apparatus while being conveyed along the paper guide 14 are supported from the printing unit 12 to the carry-out side of the paper 6. The paper discharge table 15 is arranged in this order.
[0019]
The ink detection sensor 19 is connected to a sensor signal input unit 41 as shown in FIG. The sensor signal input unit 41 is connected to various sensors such as the above-described paper leading edge detection sensor 11 of FIG. And the sensor signal input part 41 converts the signal from these sensors into the signal form suitable for information processing, and outputs it to the control part 40. FIG. Further, a key input unit 42 disposed on the front side of the upper cover 3 in FIG. 3 is connected to the control unit 40, and various key data, function data, mode designation data, and the like are transmitted from the key input unit 42. Data is entered.
[0020]
Further, a head drive unit 43 and a display unit 44 are connected to the control unit 40, and the head drive unit 43 outputs each color when black dot or color dot output data is input from the control unit 40. A drive voltage is applied to the nozzles 31b ... of the inkjet heads 31 ... corresponding to the data. The display unit 44 includes a liquid crystal display, and displays control results and control contents on the screen based on display data from the control unit 40.
[0021]
Said control part 40 has a calculating part and a memory | storage part which are not shown in figure. Various data areas such as an output data storage area and a clogged nozzle number storage area are formed in the storage unit. The output data storage area includes a data table of sub-scanning direction addresses corresponding to the nozzle numbers P (0) to P (N) of the inkjet head 31 and main scanning direction addresses corresponding to the main scanning direction of the inkjet head 31. It is formed for each color of yellow Y, cyan C, magenta M, and black B. Further, the nozzle number storage area stores the nozzle number where clogging is detected.
[0022]
In the storage unit, when a clogging of the nozzles 31b... Is detected, a head cleaning routine for performing head cleaning by a purge process or a suction process or an ink detection sensor 19 so as to eliminate the clogging. Clogging detection routine (nozzle identification means) for identifying clogged nozzles based on the detection result of ink presence / absence, whether clogged or out of ink based on the nozzle number where clogging was detected A control program comprising various control routines such as a discrimination routine (determination means) for discriminating the above is also stored. The purge process is a process for forcibly ejecting ink by raising the pressure in the nozzles 31b. The suction process is a process for sucking ink and forcibly ejecting it by setting the periphery of the opening of the nozzles 31b.
[0023]
In the above configuration, when the discrimination routine of FIG. 1 is executed at the time of mode designation by key operation, at the time of starting the recording apparatus, at the time of receiving a signal from the facsimile machine, etc., first, in the block to be discriminated. For example, the yellow Y inkjet head 31 is selected so as to select the nozzles 31b... (S1).
[0024]
Thereafter, as shown in FIG. 2, a clogging detection routine converted into a subroutine is executed, and ink is sequentially ejected from the nozzles 31 b... Of the inkjet head 31 through the ink detection sensor 19. The presence or absence of ink is detected. Then, the number of clogged nozzles F1 is obtained (S21), and the nozzle numbers of the clogged nozzles 31b ... are stored in the nozzle number storage area (S22).
[0025]
Thereafter, as shown in FIG. 1, the clogging detection routine returns to the determination routine, and it is determined whether the nozzle number F1 is a value larger than “0”. It is determined whether or not (S3). If it is determined that no clogging has occurred, it is determined whether or not the current block is the last block (S9). If it is not the last block, then in S1, for example, the magenta M inkjet head 31. Is selected, and S2 and S3 are executed again.
[0026]
On the other hand, if it is determined in S3 that clogging has occurred, it is determined whether or not the number of determination results is the Nth (S4). If not, the clogging is eliminated. After the head cleaning is performed (S5), S2 is executed again. If the clogging is not eliminated even after the execution of S2 to S5 is repeated N times, the clogged nozzle number group stored by the clogging detection routine executed before and after the head cleaning is stored in the nozzle number storage. It is determined whether or not the correlation value read from each region and the comparison between the two nozzle number groups is equal to or greater than a predetermined value K (S6).
[0027]
If it is determined in S6 that the correlation value is not equal to or greater than the predetermined value K, the clogged nozzles 31b... Are different for each clogging inspection, and thus all the nozzles 31b. In other words, it is determined that the ink has run out to the extent that sufficient ink has not been supplied, and ink out processing such as displaying the ink out or switching to the alternate reception mode is performed (S7). . On the other hand, when it is determined that the correlation value is equal to or greater than the predetermined value K, the clogged nozzles 31b. The clogging process is performed (S8). When these S7 or S8 are executed, the above S9 is executed, and the above S1 to S8 are repeatedly executed until the inspection of the final block (for example, the black B inkjet head 31) is completed. become. Note that if all the colors are tested at once, it takes a long time to check, so it is also possible to carry out each color separately.
[0028]
【The invention's effect】
[0029]
[0030]
According to the first aspect of the present invention, as described above, the abnormality detecting means for detecting ink shortage and nozzle clogging by detecting the presence or absence of ink when ink is sprayed onto the paper from the plurality of nozzles of the inkjet head. In the ink jet recording apparatus, the abnormality detection unit includes an ink detection unit that detects the presence or absence of the ink, a nozzle identification unit that identifies a clogged nozzle based on the presence or absence of the ink, and the clogging. The head cleaning means for cleaning the head so as to eliminate the nozzle specified by the nozzle specifying means is acquired before and after the head cleaning, and sufficient ink is supplied to all the nozzles based on the correlation of these nozzles. determination means but which one out of ink and clogging of the extent not supplied Is a Configurations that have. As a result, clogging occurs under the same situation as in the case of clogging in which nozzles that do not eject ink are partially detected so that ink is not sufficiently supplied to all nozzles. Since the ink outage and the clogging are discriminated based on the correlation between the nozzles, the ink outage and the clogging can be easily and reliably discriminated. Further, since the determination is made based on the nozzles before and after the head cleaning, there is an effect that it is possible to more reliably determine whether ink has run out or clogged.
[0031]
In addition, as described above, the nozzle specifying means according to claim 1 has a configuration in which all nozzles of the inkjet head are specified in block units. Thus, in addition to the effect of the first aspect, the clogged nozzle can be specified in units of blocks, so that it is possible to shorten the time required to detect ink shortage and clogging.
[Brief description of the drawings]
FIG. 1 is a flowchart of a determination routine.
FIG. 2 is a flowchart of a clogging detection routine.
FIG. 3 is a perspective view of a facsimile apparatus.
FIG. 4 is a schematic configuration diagram of a longitudinal section of a facsimile apparatus viewed from the side.
FIG. 5 is an explanatory diagram showing a schematic configuration of a printing unit.
FIG. 6 is a perspective view of an inkjet head.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Apparatus main body 4 Handset 5 Paper cassette 6 Paper 7 Paper feed roller 8 Paper feed device 11 Paper leading edge detection sensor 12 Printing part 13 Platen 19 Ink detection sensor 21 Document feeder 22 Image reading device 31 Inkjet head 31a Nozzle surface 31b Nozzle 33 Traveling Mechanism 41 Sensor Signal Input Unit 42 Key Input Unit 43 Head Drive Unit 44 Display Unit

Claims (2)

In an ink jet recording apparatus having an abnormality detecting means for detecting ink shortage and nozzle clogging by detecting the presence or absence of ink when ink is sprayed onto paper from a plurality of nozzles of the ink jet head,
The abnormality detection means is
Ink detecting means for detecting the presence or absence of the ink;
Nozzle identifying means for identifying a clogged nozzle based on the presence or absence of the ink;
A head cleaning means for cleaning the head so as to eliminate the clogging;
The nozzles specified by the nozzle specifying means are acquired before and after the head cleaning, and based on the correlation between these nozzles , ink is not sufficiently supplied to all the nozzles and clogging is not enough . An ink jet recording apparatus comprising: a determination unit that determines which one is.   2. The ink jet recording apparatus according to claim 1, wherein the nozzle specifying means specifies all nozzles of the ink jet head in divided block units.

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